Valve bag



B. T. MILLER Jan. 4, 1944.

VALVE BAG Filed Nov. 23, 1940 21??70 f/fiaf grwm Patented Jan. 4, 1944 VALVE BAG Bernard T. Miller, Wellsburg,

W. Va., assignor, by 7 direct and mesne assignments, to St. Regis Paper Company, New York, N. Y., a corporation of New York Application November 23, 1940, Serial No. 366,800

Claims. (Cl. 229-4525) This invention relates to valve bags, and particularly to valve bags where the inlet opening is securely closed after filling so that there will be no leakage through the valve.

This application is a continuation inpart of my prior application No. 257,614, filed February The primary object of the invention is to provide a bag having walls comprising aplur'ality' of plies or layers of paper and having an ordinary form of valve fia'p' formed from the socalled diamondfold. wherein-the angularly" shapedopposite ends of the bag end flaps comhaving two plies, the thickness of the plies being exaggerated throughout the drawing for clearer illustration.

In the formation of the valve construction forming the subject matter of the instant invention, the tube or bag end, is preferably longitu dinally cut a short distancea't 'a' short spaced distan'cefrom its edges, as shown at 3, and is spread openand folded to form jo'ppos'ite end bine with the triangularly shaped outerend of the valve flap to form'a diamondshape when. the bag is empty and collapsed. I 4 Y The distinguishing featureof the invention is the provision of. a transverse slit through one or more plies'offlthe valve flap through which the filling'tube may be inserted, the slit being located in the usual valve flap and the filling tube being inserted between the plies of paper comprising the bag. This slit feature lengthens the closure of the valve and'increases the protection against leakage of thecontents through the valve, and, at the same time, does not sacrifice any ofthe advantages of the diamond fold construction.

An understanding of the construction and function of the subject matter of the instant invention will be secured after a study of the following specification and the accompanying drawing, in which-- Figure 1 is a fragmentary perspective view of the valve end of a paper bag formed in accordance with the present invention; v

Figure 2 is a perspective and fragmentary view of the valve corner of a bag illustrating one step in the method of forming the leakproof valve;

Figure 3 is a perspective and fragmentary view of a portion of the valve showing the slitted valve flap in detail;

Figure 4 is a vertical sectional view of the valve construction, a filling tube being shown in dotted lines;

Figure 5 is a view similar to that shown in Figure 4, but with the filling tube removed and the valve occupying sealed relation, and

Figure 6 is a view similar to Figure 4, but showing a four ply bag with a slit through three of the plies.

Referring to said drawing, the reference numeral I designates a tubular paper bag, of multiwall construction, being composed of two or more layers of paper, the bag shown in the drawing together by means opening by the provision of a flaps 4 and 5' and'a corner valve flap 'lll'to form a valve of the common'di'amondfold. The end flap 4 isfoldedjdown and itst'riangular portion ll (formedfronr'an integral extension ofthe valveiflap' 10) is" pasted tothe uppe'r surface of the valve. flap l0 by-means 'of" the-adhesive l2.

Theopposite end flap-5 is then folded down upon thezend flap 4-, as-isitsttriangular portion l3 (formed, from anintegral extension of the valve flap [0) and the two end flaps 4 and 5 are pasted I of adhesive M to effect the bag closure.

So formed, it will be observed that the usual valve opening between the valve flap l0 and the end closure 4 is closed by reason of the adhesive l2. However, a valve opening is provided at a spaced distance outwardly of the'usual valve transversely 'extending slit of the valve flap 10, the slit l5 being so spaced from the outer edge of the bag as to leave a I lip l1 intermediate the slit I5 and the outer edge of the bag; As shownin Fig. 3, the lip I! ispasted to the inner ply of paper of the valve flap by interply adhesive I8.

When it is desired to fill the bag I, the end of the filling tube 20 attachedto the filling apparatus is introduced in the slit so that it will extend interiorly of the bag over the lip I1 and between the two layers or plies of paper from which the valve flap I 0 is formed, as shown in Fig. 4. After the bag has been filled, the bag is removed from the filling tube and the two separated plies of paper of the valve flap l0 collapse and return to abutting relation so that the valve flap I0 occupies the same horizontal plane as the lip IT, as shown in Fig. 5, thereby effectually sealing the valve against leakage.

As previously stated, the general valve flap and bag construction here involved is substantially the same as valve bags now in common use equipped with the diamond fold. In the latter construction, however, the filler tube is inserted into the bag between the valve flap l0 and the end closure flaps 4 and 5. Such a construction is objectionable because the valve flap is of such l5 provided inthe outer ply ofpaper short length that it will not effectually prevent leakage of contents therethrough. However, in the instant construction the provision of the slit IS in the upper ply of paper of the valve flap at a spaced distance outwardly of the usual valve opening materially lengthens the flap closure and increases the area of protection against leakage. Additionally, it will be noted that the filler tube is introduced into the bag between the side wall plies of the multi-wall bag, and this is desirable because such a construction serves as a bafile to discourage leakage of contents. Slit l5 must, of course, be located so that the filling tube can be inserted therethrough outside of the side flaps.

Moreover, separation of the two plies of paper of the valve flap l0 and the absence of inter-ply adhesive therebetween lends flexibility to the flap, a characteristic desirable to resist any sifting of the contents outwardly through the valve.

However, since there is ordinarily a tendency to tear the upper ply of the valve flap above the filling tube and outside of the side flaps, it is advisable to have the slit through a suilicient portion of the bag wall so as to provide strength at this point, preferably at least one-half the strength of the wall. For three or more plies this will ordinarily require a slit through a plurality of plies, in which case the slits through the several plies should substantially register so as to avoid tearing the ply that would otherwise extend outward the most above the filling tube. If the outerply is exceptionally strong, it may constitute one-half the strength of a bag having three or more plies. Conversely, if the outer ply is employed more for ornamental purposes, it is more necessary to have the slit through one or more of the strong inner plies.

Figure 6 illustrates the invention applied to a four ply bag, with the three outer plies being slit..

of the inner ply, while the three outer plies are slit at 24 to form an extension 25 of 'the overlying side flaps to which the extension is adhered by adhesive 26, similar to adhesive l2. In order that the three upper plies may be raised as a unit, it is preferable to connect them at some point, adhesive 21 being indicated for this purpose, while at the other side of slit 24 there is shown adhesive 28, similar to adhesive I8 shown in Fig. 3. Although I have illustrated a preferred embodiment of the invention it will be apparent that various changes and alterations might be made in the general form and arrangement of elements described without departing from the invention,

attention being given to the purposes of the in- 1. A bag having walls comprising a plurality of plies of paper and having an end closure comprising end flaps of oppositely infolded portions of the bag wall and side flaps of oppositely infolded portions of the bag wall overlying the end flaps, and adhesive uniting all of said flaps, one of said end flaps having a transverse slit through its outer portion beyond the overlying side flaps and through at least substantially half its strength.

2. A bag having walls comprising a plurality of plies of paper and having an end closure comprising end flaps of oppositely infolded portions of the bag wall and side flaps of oppositely infolded portions of the bag wall overlying the end flaps, and adhesive uniting all of said flaps, one of said end flaps having a transverse slit through a pinrality of plies beyond the overlying side flaps.

3. A bag having walls comprising a plurality of plies of paper and having an end closure comprising end flaps of oppositely infolded portions of the bag wall and side flaps of oppositely infolded portions of the bag wall overlying the end flaps, and adhesive uniting all of said flaps, one of said end flaps having substantially registering transverse slits through a plurality of outer plies beyond the overlying side flaps.

4. A bag having walls comprising a plurality of plies of paper and having an end closure comprising end fiaps of oppositely infolded portions of the bag wall and side flaps of oppositely infolded portions of the bag wall overlying th end flaps, adhesive uniting all of said flaps, one of said end flaps having a transverse slit through a pluralityv of plies beyond the overlyingside flaps, the slit plies being attached to each other on the side of the slit towards the side flaps.

5. A bag having walls comprising a plurality of plies of paper and having an end closure comprising end flaps of oppositely infolded portions of the bag wall and side flaps of oppositely infolded portions of the bag wall overlying the end flaps, and adhesive uniting all of said flaps, one of said end flaps having a transverse slit through its outer portion beyond the overlying side flaps and through at least substantially half its strength, and means attaching the outer plies outside of the slit to the unslit inner portion of the bag wall.

BERNARD T. MILLER. 

